Objects in the world appear to have stable identities, sometimes more stable than they actually are. This is thought to be facilitated by perceptual serial dependence, and has been reported for orientation, faces, attractiveness, position, among various other visual object domains. The mechanism for serial dependence remains unclear: it has been argued that serial dependence may occur at the level of perception, at the level of decisions, or that serial dependence, being an influence of the past on the perception of the present, may simply be a byproduct of working memory. Here we tested individual differences in perceptual serial dependence for orientation and faces in addition to measures of working memory capacity to try to determine whether serial dependence is indeed correlated with memory. There were substantial individual differences in perceptual serial dependence, but the correlation between orientation and face serial dependence across subjects was approximately zero and non-significant. This indicates that there is some degree of independence and likely separable processes that contribute to serial dependence in the perception of faces and orientation, while also providing evidence against the possibility that serial dependence is a stimulus invariant 'decision' bias. We then compared serial dependence in face and orientation perception to measures of working memory capacity, including an operation span task and a change detection task. While the estimates of working memory capacity were stable across sessions within subjects, each of these measures of working memory was only weakly and non-significantly correlated with perceptual serial dependence of either faces or orientation. These results build on previous ones (Zhang et al, 2015) suggesting that serial dependence operates independently from traditional measures of working memory. They further raise the possibility that serial dependence operates at multiple levels of visual processing.